Composite structures having a gas barrier layer containing aluminum have hitherto been proposed for use in electronic devices such as a liquid crystal display of a display apparatus, and examples of the composite structures include a composite structure having a transparent gas barrier layer composed of a reaction product of aluminum oxide particles and a phosphorus compound (see Patent Literature 1).
Patent Literature 1 discloses a method for forming the gas barrier layer, in which a coating liquid containing aluminum oxide particles and a phosphorus compound is applied onto a plastic film, then dried and heat-treated.
However, the above conventional gas barrier layer may experience deterioration in gas barrier performance and fail to maintain sufficient gas barrier properties over a long period of time under hot and humid conditions.
In recent years, electronic devices such as a light-emitting diode (LED) have come to incorporate quantum dots as a fluorescent material that converts the wavelength of incident light and emits the wavelength-converted light. A quantum dot (QD) is a light-emitting semiconductor nanoparticle that typically has a diameter on the order of 1 to 20 nm. In the quantum dot, electrons are quantum-confined within a three-dimensional, sharply-outlined, nanoscale semiconductor crystal. Such fluorescent quantum dots are prone to aggregation and can be degraded, for example, by oxygen, for which reason they are generally dispersed in a medium such as a resin when used.
Patent Literature 2 describes a flash module having quantum dots dispersed in a matrix composed of a sol, gel, polymethylmethacrylate (PMMA), polystyrene, polycarbonate, UV-curable resin, or thermosetting resin such as an epoxy.
Even when fluorescent quantum dots are dispersed in a resin, however, they may be degraded, for example, by atmospheric oxygen or water.